ICTIOBUS 67 



broadest at its middle; cheek shorter and not so deep as in Carpiodes, 

 the lower posterior border of the preopercle a gentle curve, the eye 

 evidently closer to the angle of the preopercle than to the upper corner 

 of the gill-cleft; pharyngeal bones broad, but thin and weak, the teeth 

 short and compressed; vertebras 36; air-bladder in two parts; dorsal fin 

 long, with from 25 to 30 rays, the anterior rays produced, about ^ the 

 length of base of fin; scales roundish; lateral line complete; color rather 

 dark, never silvery; sexual differences slight. 



Mississippi and Ohio rivers and their larger tributaries; three 

 species known, all of them common to our larger streams. These 

 fishes are the largest in size of the Catostomidce, not infrequently 

 reaching a length of 3 feet and a weight of 50 pounds. The name 

 " buffalo -fish " refers to the bull-like hump at the nape in old indi- 

 viduals. The relationships of these fishes with the carp are remote. 

 The view, not uncommon among fishermen, that carp and buffalo 

 interbreed is not supported by any facts in our knowledge, and is 

 probably based solely on the superficial* resemblance of the buffalo 

 and the carp in the form of the body and of the dorsal fin. 



The species are gregarious and nocturnal, coming out at night 

 on bars not frequented by them by day, and where they may be 

 readily reached by the seine. Fishermen report that they move 

 into lakes in cold weather, spending the winter as much as possible 

 in weedy water. They are said to dig holes in the bottom, like the 

 German carp. This genus includes closely related species of identi- 

 cal general distribution in Illinois, but differing noticeably in respect 

 to the structures of food selection, and likewise to some extent in 

 situations preferred, one of the more abundant species especially 

 (bubalus) habitually occurring in deeper water than the other. In 

 the red-mouth buffalo {cyprinella) the pharyngeal jaws are lighter 

 than in bubalus, their teeth have a smaller grinding surface, and 

 the gill-rakers are longer and more numerous. 



The feeding habits of the buffaloes, like those of all the fishes 

 inhabiting the muddy waters of central Illinois, are difficult of 

 observation, but several fishermen and other river men have re- 

 ported to us that these fishes have the habit of whirling around in 

 shallow water, or plowing steadily along with their heads buried in 

 the mud, their bodies in an oblique position, and their tails occa- 

 sionally showing above the surface. These operations have nothing 

 to do with the act of spawning, and probably indicate a search for 

 small mollusks and insect larvae living in the mud. Buffaloes 



*The presence of the conspicuous maxillary barbels in the carp, entirely want- 

 ing in the buffalo, and the heavy serrated dorsal spine of the carp — all fins of the 

 buffalo being spineless — are sufficient marks of distinction. 



